Removable orthodontic appliances are used to retain teeth in an aligned position and to move teeth. Retaining the orthodontic appliance on the teeth has long been a problem. Traditional Hawley type appliances use metal clasps for retention. These metal clasps are adjustable: although, retention has been difficult as evidenced by the variety of clasps, such as ball clasps and Adams clasps, developed to improve the retentive capabilities. The arrival of thermoformed appliances introduced an all plastic appliance without metal clasps for retention. Attempts, with limited success, have been made to add retentive clasps. The thermoforming process does not readily enclose wires. Wires are held in with acrylic which requires a thermoforming material which is compatible and will fuse with the acrylic. Some of the best thermoforming materials are not compatible with acrylic. Pliers have been developed to dent the plastic material in a variety of shapes. None of the devices have been successful in making the vacuum-formed appliances more retentive after the appliance has been constructed.